/**
 *	用js实现MD5加密
 */
function md5(s){

	var hexcase = 0;//十六进制格式输出。 0 - 小写1 - 大写
	var b64pad = '';//基于64位填充字符。 "="严格符合RFC标准

	/* 编码为utf-8 , 假设input的值为utf-16 */
	function str16tostr8(input){
		var output = '';
		var i = -1;
		var x, y;
		//console.log(input);
		while(++i < input.length){
			x = input.charCodeAt(i);/* 解码utf-16 */
			y = i + 1 < input.length ? input.charCodeAt(i+1) : 0;
			if(0xD800 <= x && x <= 0xDBFF && 0xDC00 <= y && y <= 0xDFFF){
      			x = 0x10000 + ((x & 0x03FF) << 10) + (y & 0x03FF);
      			i++;
    		}
    		/* 编码为utf8的 */
    		if(x <= 0x7F)
      			output += String.fromCharCode(x);
    		else if(x <= 0x7FF)
      			output += String.fromCharCode(0xC0 | ((x >>> 6 ) & 0x1F),
                                   			  0x80 | ( x         & 0x3F));
    		else if(x <= 0xFFFF)
      			output += String.fromCharCode(0xE0 | ((x >>> 12) & 0x0F),
                   			                  0x80 | ((x >>> 6 ) & 0x3F),
                            		          0x80 | ( x         & 0x3F));
    		else if(x <= 0x1FFFFF)
      			output += String.fromCharCode(0xF0 | ((x >>> 18) & 0x07),
                                    		  0x80 | ((x >>> 12) & 0x3F),
                                    		  0x80 | ((x >>> 6 ) & 0x3F),
                                    		  0x80 | ( x         & 0x3F));
		}
		//console.log(output);
		return output;
	}

	/**
	 *	把原始字符串转化为16为字符串
	 *	@param string input 输入值
	 */
	function rstr2hex(input){
  		try { 
			hexcase 
		}catch(e){ 
			hexcase=0; 
		}
  		var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
  		var output = "";
  		var x;
  		for(var i = 0; i < input.length; i++){
    		x = input.charCodeAt(i);
    		output += hex_tab.charAt((x >>> 4) & 0x0F)
           		   	  +hex_tab.charAt( x       & 0x0F);
  		}
  		return output;
	}
	

	/**
	 *	添加整数,封装为2^32形式.
	 *	这里采用16位内部操作解决js解析器错误.
	 */
	function safe_add(x, y){
		var lsw = ( x & 0xFFFF) + ( y & 0xFFFF );//限制在32位
		var msw = ( x >> 16) + (y >> 16) + ( lsw >> 16);//缩小2^16
		return (msw << 16) | (lsw & 0xFFFF);
	}

	/**
	 *	原数据转化一个数组的低位字符
	 *	字符大于255 && 高字节忽略
	 *	@param string input 接收的字符串
	 *	@return array
	 */
	function rstr2binl(input){
		var output = Array( input.length >> 2);
		for(var i = 0; i < output.length; i++){
			output[i] = 0;
		}
		for(var i = 0; i<input.length*8;i += 8){
			output[i>>5] |= (input.charCodeAt(i / 8) & 0xFF) << (i%32);
		}
		return output;
	}

	/**
	 *	把一个低位字节转化字符串
	 */
	function binl2rstr(input){
  		var output = "";
  		for(var i = 0; i < input.length * 32; i += 8)
   			output += String.fromCharCode((input[i>>5] >>> (i % 32)) & 0xFF);
  		return output;
	}

	/**
	 *	位转为一个32位数字的左边
	 */
	function bit_rol(num, cnt){
		//console.log(num >>> (32-cnt), (num << cnt));
		return (num << cnt) | (num >>> (32-cnt));
	}

	/**
	 *	这些方法实现四种基本运算的算法使用。
	 */
	function md5_cmn(q, a, b, x, s, t){
		return safe_add(
					bit_rol(
						safe_add(
							safe_add(a, q),
							safe_add(x, t)
								)
						,s)
			   ,b);
	}

	function md5_ff(a, b, c, d, x, s, t){
  		return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
	}

	function md5_gg(a, b, c, d, x, s, t){
  		return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
	}

	function md5_hh(a, b, c, d, x, s, t){
  		return md5_cmn(b ^ c ^ d, a, b, x, s, t);
	}

	function md5_ii(a, b, c, d, x, s, t){
  		return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
	}
	
	/**
	 *	低位字节计算数组的MD5,和一位长度
	 */
	function binl_md5(x, len){
		/* 填充 */
		x[len >> 5] |= 0x80 << ((len) % 32);
		x[(((len + 64) >>> 9) << 4) + 14] = len;

		var a =  1732584193;
		var b = -271733879;
		var c = -1732584194;
		var d =  271733878;

		for( var i = 0; i < x.length; i += 16){
			var olda = a;
			var oldb = b;
			var oldc = c;
			var oldd = d;

			a = md5_ff(a, b, c, d, x[i+ 0], 7 , -680876936);
			d = md5_ff(d, a, b, c, x[i+ 1], 12, -389564586);
			c = md5_ff(c, d, a, b, x[i+ 2], 17,  606105819);
			b = md5_ff(b, c, d, a, x[i+ 3], 22, -1044525330);
			a = md5_ff(a, b, c, d, x[i+ 4], 7 , -176418897);
			d = md5_ff(d, a, b, c, x[i+ 5], 12,  1200080426);
			c = md5_ff(c, d, a, b, x[i+ 6], 17, -1473231341);
			b = md5_ff(b, c, d, a, x[i+ 7], 22, -45705983);
			a = md5_ff(a, b, c, d, x[i+ 8], 7 ,  1770035416);
			d = md5_ff(d, a, b, c, x[i+ 9], 12, -1958414417);
			c = md5_ff(c, d, a, b, x[i+10], 17, -42063);
			b = md5_ff(b, c, d, a, x[i+11], 22, -1990404162);
			a = md5_ff(a, b, c, d, x[i+12], 7 ,  1804603682);
			d = md5_ff(d, a, b, c, x[i+13], 12, -40341101);
			c = md5_ff(c, d, a, b, x[i+14], 17, -1502002290);
			b = md5_ff(b, c, d, a, x[i+15], 22,  1236535329);

			a = md5_gg(a, b, c, d, x[i+ 1], 5 , -165796510);
			d = md5_gg(d, a, b, c, x[i+ 6], 9 , -1069501632);
			c = md5_gg(c, d, a, b, x[i+11], 14,  643717713);
			b = md5_gg(b, c, d, a, x[i+ 0], 20, -373897302);
			a = md5_gg(a, b, c, d, x[i+ 5], 5 , -701558691);
			d = md5_gg(d, a, b, c, x[i+10], 9 ,  38016083);
			c = md5_gg(c, d, a, b, x[i+15], 14, -660478335);
			b = md5_gg(b, c, d, a, x[i+ 4], 20, -405537848);
			a = md5_gg(a, b, c, d, x[i+ 9], 5 ,  568446438);
			d = md5_gg(d, a, b, c, x[i+14], 9 , -1019803690);
			c = md5_gg(c, d, a, b, x[i+ 3], 14, -187363961);
			b = md5_gg(b, c, d, a, x[i+ 8], 20,  1163531501);
			a = md5_gg(a, b, c, d, x[i+13], 5 , -1444681467);
			d = md5_gg(d, a, b, c, x[i+ 2], 9 , -51403784);
			c = md5_gg(c, d, a, b, x[i+ 7], 14,  1735328473);
			b = md5_gg(b, c, d, a, x[i+12], 20, -1926607734);

			a = md5_hh(a, b, c, d, x[i+ 5], 4 , -378558);
			d = md5_hh(d, a, b, c, x[i+ 8], 11, -2022574463);
			c = md5_hh(c, d, a, b, x[i+11], 16,  1839030562);
			b = md5_hh(b, c, d, a, x[i+14], 23, -35309556);
			a = md5_hh(a, b, c, d, x[i+ 1], 4 , -1530992060);
			d = md5_hh(d, a, b, c, x[i+ 4], 11,  1272893353);
			c = md5_hh(c, d, a, b, x[i+ 7], 16, -155497632);
			b = md5_hh(b, c, d, a, x[i+10], 23, -1094730640);
			a = md5_hh(a, b, c, d, x[i+13], 4 ,  681279174);
			d = md5_hh(d, a, b, c, x[i+ 0], 11, -358537222);
			c = md5_hh(c, d, a, b, x[i+ 3], 16, -722521979);
			b = md5_hh(b, c, d, a, x[i+ 6], 23,  76029189);
			a = md5_hh(a, b, c, d, x[i+ 9], 4 , -640364487);
			d = md5_hh(d, a, b, c, x[i+12], 11, -421815835);
			c = md5_hh(c, d, a, b, x[i+15], 16,  530742520);
			b = md5_hh(b, c, d, a, x[i+ 2], 23, -995338651);

    		a = md5_ii(a, b, c, d, x[i+ 0], 6 , -198630844);
    		d = md5_ii(d, a, b, c, x[i+ 7], 10,  1126891415);
    		c = md5_ii(c, d, a, b, x[i+14], 15, -1416354905);
    		b = md5_ii(b, c, d, a, x[i+ 5], 21, -57434055);
    		a = md5_ii(a, b, c, d, x[i+12], 6 ,  1700485571);
    		d = md5_ii(d, a, b, c, x[i+ 3], 10, -1894986606);
    		c = md5_ii(c, d, a, b, x[i+10], 15, -1051523);
    		b = md5_ii(b, c, d, a, x[i+ 1], 21, -2054922799);
    		a = md5_ii(a, b, c, d, x[i+ 8], 6 ,  1873313359);
    		d = md5_ii(d, a, b, c, x[i+15], 10, -30611744);
    		c = md5_ii(c, d, a, b, x[i+ 6], 15, -1560198380);
    		b = md5_ii(b, c, d, a, x[i+13], 21,  1309151649);
    		a = md5_ii(a, b, c, d, x[i+ 4], 6 , -145523070);
    		d = md5_ii(d, a, b, c, x[i+11], 10, -1120210379);
    		c = md5_ii(c, d, a, b, x[i+ 2], 15,  718787259);
    		b = md5_ii(b, c, d, a, x[i+ 9], 21, -343485551);

    		a = safe_add(a, olda);
    		b = safe_add(b, oldb);
   			c = safe_add(c, oldc);
    		d = safe_add(d, oldd);
  		}
  		return Array(a, b, c, d);
	}
	
	/**
	 *	计算原始字符串的MD5值
	 */
	function rstr_md5(s){
		return binl2rstr(binl_md5(rstr2binl(s), s.length * 8));
	}

	/**
	 *	计算MD5的值
	 */
	function hex_md5(s){
		return rstr2hex(rstr_md5(str16tostr8(s)));	
	}

	/* 测试 */
	function hex_md5_test(s){
		console.log('md5加密测试:'+hex_md5(s));
	}
	hex_md5_test(s);
	


	/**
	 * 转化为base64编码格式
	 */
	function rstr2b64(input){	
		try { 
			b64pad 
		} catch(e) { 
			b64pad=''; 
		}
  		var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  		var output = "";
  		var len = input.length;
  		for(var i = 0; i < len; i += 3){
    		var triplet = (input.charCodeAt(i) << 16)
            		    | (i + 1 < len ? input.charCodeAt(i+1) << 8 : 0)
                		| (i + 2 < len ? input.charCodeAt(i+2)      : 0);
    		for(var j = 0; j < 4; j++){
      			if(i * 8 + j * 6 > input.length * 8) output += b64pad;
      			else output += tab.charAt((triplet >>> 6*(3-j)) & 0x3F);
    		}
  		}
  		return output;
	}

	/**
	 *	64MD5 + base64加密
	 */
	function b64_md5(s){ 
		return rstr2b64(rstr_md5(str16tostr8(s))); 
	}
	console.log('base64格式:'+b64_md5(s));


	/**
	 *	原始字符串转化为任意编码格式
	 *	@param string input 输入的值
	 *	@param string encoding 编码格式
	 */
	function rstr2any(input, encoding){
  		var divisor = encoding.length;
  		var i, j, q, x, quotient;

  		/* Convert to an array of 16-bit big-endian values, forming the dividend */
  		var dividend = Array(Math.ceil(input.length / 2));
  		for(i = 0; i < dividend.length; i++){
    		dividend[i] = (input.charCodeAt(i * 2) << 8) | input.charCodeAt(i * 2 + 1);
  		}
  		/*
   		 * Repeatedly perform a long division. The binary array forms the dividend,
   		 * the length of the encoding is the divisor. Once computed, the quotient
   		 * forms the dividend for the next step. All remainders are stored for later
   		 * use.
         */
  		var full_length = Math.ceil(input.length * 8 /
                          (Math.log(encoding.length) / Math.log(2)));
  		var remainders = Array(full_length);
  		for(j = 0; j < full_length; j++){
    		quotient = Array();
    		x = 0;
    		for(i = 0; i < dividend.length; i++){
      			x = (x << 16) + dividend[i];
      			q = Math.floor(x / divisor);
      			x -= q * divisor;
      			if(quotient.length > 0 || q > 0)
        			quotient[quotient.length] = q;
    			}
    			remainders[j] = x;
    			dividend = quotient;
  			}
  			/* Convert the remainders to the output string */
  			var output = "";
  			for(i = remainders.length - 1; i >= 0; i--)
    			output += encoding.charAt(remainders[i]);

  			return output;
		}

		function any_md5(s, e){ 
			return rstr2any(rstr_md5(str16tostr8(s)), e); 
		}
		
		//转化为任意编码
		console.log("任意编码格式:"+any_md5(s,'asdfasdfsdf'));


	return hex_md5(s);
};
